text: Magnetization transfer (MT) is a technique to enhance image contrast in certain applications of MRI.
  Bound protons are associated with proteins and as they have a very short T2 decay they do not normally contribute to image contrast. However, because these protons have a broad resonance peak they can be excited by a radiofrequency pulse that has no effect on free protons. Their excitation increases image contrast by transfer of saturated spins from the bound pool into the free pool, thereby reducing the signal of free water. This homonuclear magnetization transfer provides an indirect measurement of macromolecular content in tissue. Implementation of homonuclear magnetization transfer involves choosing suitable frequency offsets and pulse shapes to saturate the bound spins sufficiently strongly, within the safety limits of specific absorption rate for MRI.
  The most common use of this technique is for suppression of background signal in time of flight MR angiography. There are also applications in neuroimaging particularly in the characterization of white matter lesions in multiple sclerosis.